Magneto



March 30 1926. 1,578,637

P.'B ROWN MAGNETO Filed Feb. 25, 1924 4 SheetS-She8t 2 INVENTOR 7?ATTORNEYS March 30,1926. 1,578,637

' P. BROWN MAGNETO Filed Feb. 25, 1924 4 Sheets Sheet Z5 ATTORNEYS March30 Q 1926. 1,578,637

P. BROWN MAGNETO Filed Feb. 25, 924 4 Sheets-Sheet 4 INVENTOR BYWATTORNEYS Patented Mar. 30, 1926.

hair so are rarer PHELPSBROWN, 05F :SERIMGFIELD, I'JIASSACEUSETTSE'MAGNETQ- Applicationifiled February25, 1924. SeriaLNo. 695,096.,

To all whom it may concern:

Be 1t known that I, PHELPS BROWN, a cit1 Zen of the United States,reslding at Sprlngfield, in the county of Hampden and State ofMassachusetts have invented new and useful Improvements in liiagnetos,of which while desirable from the point 01" view ot" low reluctance ofthe magnetic circuit, neces-' saril tends to create noise andwhileenough has been done in the past to prevent excessive noise of contactin magnetos intended for relatively low speed operation, the priordevelopments are not sinlicient to overcome the noise of contact whenthe armature is operated at relatively high speeds, such as arenecessary when the mag netos are to be used in connectionwithlinulticylinder engines, such as are used in tractors, trucks,automobiles, aeroplanes and the like. The driving of the armature aw yfrom its poles at speeds independent of eng ne speeds is important inmagnetos operated by relatively slow speed engines and it is importantin any event for starting purposes. In magnetos operated by high speedengines, however, the armature can be operated at speeds dependent onengine speed and armature speeds equal to, or greater, than'thespeedsobtained by spring drive of the armature can be obtained.

The present invention is directed to the provision oLt a magnetointended for operation with relatively high speed "engines and theinvention seeks to provide a magneto which is suitable for'multi-cylinder engines, such as the engines used on tractors, motortrucks, automobiles, aeroplanes and so forth.

In adapting a' magneto, oi the general class described, for the new andextended field of service above Serena, one ofthe characteristicfeatures ot the magneto, hitherto accepted almost as landmarlq'has hadto be dispensed with, at leastat'certain desirable on account of theensuing noise.

stages ot the 'magneto operation. This tea; ture it that of physicalcontact of the'armature with its poles. 'Ihe'preventi'on of "such.contact at high armature speeds is obviously It is also desirableand-practicaily essential to reducevibration and to prevent excessiveWear on the parts which would otherwise occur due totlie high speed"operation of the armature. At the same time, contact of the armaturewith its poles may, undercertain conditions, particularly at crankingspeeds, be desirable.

It is therefore an object of this ingention to provide, in 1 a magnetoof the, general class described, means Whereby'the arma ture may beprevented from contaetingwitlr its poles, as and whendesir'edQ It isalso an object of the. iHVQIlUOIlltO provide means whereby theminimumair gap between'the armature and its poles may be varied, as andwhen desired, and preferably, althoughf'not necessarily, varied -tr om apredetermined maximum gap to zero. I

Another object is to provide means con trolled by variation of theminimum air gap for varying the timingxof the spark "generated. f

Anothercb'i'ect :ot the invention is to pro vide, ina magneto of thegeneral class'described, means "whereby the electricalout out maybe'varied and controlled,- as dsiredf; Anotherobject of the invention istopro vide aspecifically improved armature :actu

ating mechanism, characterized in that the armature isoperated atspeedsproportionate to engine speeds" and withoutthe use of elasticdriving means, such as springs.

Another object of "the invention is toprovicle an armature actuatingmechanism,:consistingot' a quick throw cam driven by'the engine, andconnections therefromto the armature for moving the latter by anwin+elastic transmission of torce,such connections including a lever, thefulcrum otwhich is adjustable to control the degreeot approach otthearmature toward-its poles. Another object of theinvention is toprovideimprovedfmeans for controlling the breaker points which open andclosethe choke winding of "the magneto.

More particularly; itis an object-of the invention to'provicie meansindependent ot the armature for controlling the breaker points to theextent of holding themopen vention.

for the purpose of enabling the flux to build up rapidly in the magneticcircuit. Ordinarily, the breaker points are connected for operation fromthe armature and close when the armature closely approaches the poles,thereby forcing the flux to build up against a short circuited chokewinding which retards the action. While the latter arrangement isdesirable if sur'licient time intervals are available, as in inagnetosoperating at relatively low armature speeds, it is not commerciallysatisfactory in the present case where high speed operation of thearmature is desired and where a rapid building up of flux isconsequently necessary.

Other objects and advantages will appear in the following descriptionand in the illustrative embodiment of the invention in the accompanyingdrawings, in which Fig. 1 is a side elevation view of a magnetoembodying the invention, certain parts being broken away to revealinterior construction;

Fig. 2'is a front elevational view thereof with the front casing removedto show cer tain magneto parts;

Fig. 3 is an elevational view taken from the right hand side of Fig. 2;

Fig. 4: is a diagrammatical view illustrative of the magnetic andelectrical circuits of the magneto; and

Figs. 5, 6, 7 and 8 are fragmentary views, taken similarly to Fig. 1 andillustrating successive steps in the operation of the magneto.

Referring to these drawings :The magneto include a suitable source ofmagnetic flux, herein shown as a series of bar magnets 10, to the polesof which are suitably and magnetically connected two laterally spacedand depending cores 11, preferably made up of laminations in the usualmanner. On each core 11 is a suitable generating coil 12 and a chokingcoil 13, the coils 12 being suitably connected, as in series asindicated in Fig. 4:, and the coils 13 being similarly connected, asthere indicated. An armature 14, preferably made up of la1ninations inthe usual manner, is mounted in any suitable manner for movement towardand away from the lower end of at least one of the cores, and usuallyaway from the lower ends of-both of the cores 11. These core endsconstitute magnetic poles and the object of the armature movement,however effected, is to vary the reluctance of the magnetic circuit,whatever its particular nature. As shown, such circuit comprises thesource 10, cores 11, armature 1 1, and the air gaps between the latterand its poles. The precise arrangement of the magnetic circuit and themeans for effecting variations therein are not essential features of thepresent in- The terminals of the connected coils 12,

which together form the generating winding, are connected to theignition system in any usual and desired manner. Usually one terminal ofthe winding is grounded, as indicated at 15, and the other terminal isconnected, as by a wire 16, to a spark plug 8, or the wire '16 may, whenthe magneto is used in connection with mnlti-cylinder engines, lead to adistributer. The choking winding, afforded by the connected coils 13, isarranged in an electrical circuit which can be opened and closed by twocooperating breaker points 17 and 18, one of which, as 18, is connectedmetallically, as will appear, to the frame of the machine and is thusgrounded. :One terminal of the choking winding is likewise grounded, asindicated at 19, and the other terminal is connected by a wire 20 to abreaker point 17. A condenser 21 is bridged across the breaker points inthe usual manner, being connected by wires 22 and 23 to point 17 andground 19, respectively.

The breaker point 17, as shown in Fig. 1, is stationarily, butadjustably, fixed in arm insulated from the upper end of a tube 24,which in turn is suitably fixed in a metallic but non-magnetic part 25of the magneto frame. The breaker point 18 is mounted in the upper endof a cylinder 26 which is slidable in'tube 24: and metallicallyconnected therewith and thus grounded to the magneto frame. Fixed tocylinder 26 is a stem 27 which extends out of the open lower end of tube24 and passes loosely through an abutment 28, fixed on armature 141, andis provided below such abutment, with an adjustable abutment 29 forengagement with. the latter. The stem 27 passes freely through feltwashers 3O superposed on abutment 28 and provided for lubricatingpurposes, and a spring 31 acts between the latter and the base ofcylinder 26, tending to hold the abutments 28 and 29 in contact and,under the conditions illustrated in Fig. 1, tending to hold the breakerpoints in close contact.

The magneto parts, above described, are all suitably supported from aframe which is secured, as by bolts 32, to the engine, or a part of theframe thereof,'herein exemplified by a bracket A complete disclosure ofthe construction of the magneto proper will be found in the copendingapplication of Phelps Brown and Terrence G. Louis, filed July 18, 1323,under Serial No. 652,356. A detailed description of the magnetoconstruction is not, however, essential for an understanding of thepresent invention.

The magneto, as thus far described, will serve as an illustrativeexample of one suitable type of magneto in which the invention may beembodied. Many other magnetos of similar character are adaptable to thepresent invention and the foregoing description is intended to set forthmerely a general type andthe details of the constructionand arrangmentof parts are not important to, or essential parts of, the presentinvention.

Thearmature 14; may be: mounted for movement toward and away fromthe endof one or both'of the cores 11 in anysuitable manner, as above setforth. As shown, the armature is slidable in austraight line on a guidepin which is fixed to the frame member 25 and extends downwardlytherefrom, passing freely through the centralportionof armature 1%..Centrally fixed tothe latter and depending therefrom is a fork 36, thedependingwarms of which are bridged and interconnected by'av pin 37. Thelatter is received in the forked outer extremity of an arm, 38, integralwith which isa depending arrn 39,the'two arms forming a bell cranlrleverwhich is pivotaliy mounted at the junction ofithe arms. on a stud 4:0;The arm 39 constitutesia follower for a cam e1, fixed. on a shaftJiQ,suitably drivenv-at the desired speed ratio from the engine crankshaft.A spring 13, mounted in a recess 44 provided in bracket 33, acts onthe'lower end. of an arm 39 and tends to hold it in engagementwith: came1.

The armature operating means isvdifi'eiw enti ated fromthatiordinarilyemployed in magnetos of this generalatype in that the armature is at-alltimes'opera-ted by an. inelastic t 'ansmissionfrom the driving shaft.

The usual drive spring, which .is stressed during the revolution ofsuchshaft'and subsequent-ly released to move the armature at.

a speed independent of engine speed, is entirely dispensed with for thepresent Imagnetoisintended for use with engines wherein armature speeds,equalto or in excess oi those obtainable by drive springs, can beobtained by the operating means herein:

disclosed.

he stud is fixed to a collar 25 in eccentric relation therewith andprojects out- Wardly therefrom in the fashion of a crank pin. tiontherewith, and thus eccentrically with relation to stud. 45,: is a shaft4:6 which is mounted to turn in. a bearing lbracket 33. Integral withbracket 33 and concentrically disposed. with relation to shaft 46 is asector 48, the curved edge-4 9 of which is notched, as shown in Fig.Fixed to shaft 4:6 is-an arm 50, the hub of" which functions as acollarand cooperates with; collar and the endufacesxo'f bearing.

4:? to limit the end play of shaftttitherein. Arm 50 isadaptedto swingadjacent sector 4-8 and is provided with a cylinderical portion 51 whichoverliesthe curved edgedi). Mounted in portion 51 is a'spring presseddetent 52 which is constantly urged toward the edge a9 and is adapted toengage in any ot the notches therein to hold shaft i6 in variouspositionsof angular adjustment in Fixed to collar L5 in concentric1Blz.-

( formed on:

bearing 27. Byturningarm 50, the stud- 40" may be raised :and loweredand 'alsomoved laterally with respect-to the center of shaft 46 andconsequently the pivotalv axis of the armature actuating bell cranklever may be varied. The important effect of this variae:

tion of the location of the pivotal. axis is tocontrol theadegree towhich the armature l-ii approaches theends of cores 11-orrthe-extent .oftheininimum air gap therebetweeir. The stud lO maybe so-positioned thatarmature 14: can come into physicalucontact with cores 11 or it may be'so positioned, as illustrated; to prevent .suchcontact and so limit thedegree of approach of the-armature to cores 11 that a minimum air. gap:such 4r,

(Fig. 1), is left therebetween; Alsothe extent of this air gap 00 may bevaried within limits, as desired.

The results described follow for two areasons. First, if thestroke'of'the armature 14 be regardedas constant, then thelocationofthis stroke with respect to fixed v parts of the magneto is-varied bythe vertical movements ofadjustments ofstud; 40. Second, theverticalmovementsof'stud 10,1 asa matter of fact, cause camel toengage'.

arm 39 along. lines of'contact whicharei at.

difierent distances from the center of-stud' .420, whereby the efiective length offarln 39 may be varied to vary the extent of stroke 53 isa suitable cam follower 58, herein' shown as a lever pivoted to bracket33 at 59 and underlying cam 53, beingyieldingly held. in; contact-withthe latter by" a (spring:

59. The-free endjof lever 58 is be'ntatrigh'tangles, as shown at 60 inFig.12, tolievertically beneath the end of thwbreakerrpoint. stem 27. Alink: 61, one-end oiiiwhiclnis inturned and engaged in a :hole in theend 60 of lever'58', extends upwardly'and enters freely into the bottomof sleeve 62. The latter is fixed, preferably in an adjustable manner,.as shown in Fig. 1, .to-the lower end of stem'27 and-below the latter:has a cylindrical bore 63 in whiclra head'6 l, fixedon link 61,.isfreely slidable'; The arrangement is such that stem '27 and-.theattachedsleeve 62 may move downwardl independently of link: 61, whereby thebreaker points 17 and l3'may beseparated in. the usualway by theengagement of abutment 28 on the armature with abut; nient 29 on stem27. The arrangement is also such that lever 58 maybe depressed by cam53, thus drawing link 61 downwardly until head 64 engages and movessleeve 62 and thus moves the breaker point 18. The various parts in thebreaker point operating mechanism bein adjustable, they may be adjustedand timed so that either means can operate the breaker points. l'lypreference, however, the latter are opened in the usual manner by themovement of the armature and are prevented from again closing by theoperation of cam 53 until the armature has reached the upper limit ofits travel. The prevention of the closing of the breaker points isimportant in that the flux is permitted to build up rapidly in themagnetic circuit, since the choking coils 13 are prevented fromexercising their retarding influence which would occur if the breakerpoints were in contact. The breaker points are allowed to close afterthe armature has dwelled in its upper position for a suflicient intervalto permit the flux to build up in the magnetic circuit.

The armature driving means, as above disclosed, includes a cam anddesirably this cam is 'a quick throw cam of the general typeillustrated. The particular contour of cam 41, and the manner in whichit coacts with follower 39, is important because of the resultingeffects obtained in the operation of the armature and the breaker pointmechanism. The greater portionof cam 41 is concentric with shaft 42 andthe concern tric portions are made up of a relatively large low dwellportion 65 and a relatively small high dwell portion 66. The portions 65and 66 are connected by rise and fall portions 67 and 68,respectively,-these portions being straight and arranged in outwardlyconverging relation. In the'counterclockwise rotation of cam 41 (asviewed in Fig. 1) the portion 6'? will eventually move into parallel andcontiguous relation with the follower 39. This occurs after cam 41 hasmoved through the angle a and the relative positions of the parts whichthen obtain is illustrated in Fig. 5. Thereafter, continued movement ofcam 41 moves the follower and the armature 14 but the movement of thelatter, at least in its initial stages, is relatively slow as thecontiguous faces 39 and 67 begin to move out of parallelism. Therelatively slow initial movement is followed by a progressively andrapidly increasing movement which reaches its maximum as the parts moveinto the relative positions shown in Fig. 6. lhe condition thereillustrated is that which ob tains at'the end of the mov ment of follower 89. During the movement of cam 41 through the relatively smallangle 5, the armature 14 is moved away from poles ll and to the lowerlimit of its downward stroke. The action is therefore not only veryquick but the armature is started in motion relatively gradually and'itn. as

little shock as possible. The relatively gradual initial action isespecially important when the condition of physical contact existsbetween the armature and its cores. The powerful magnetic hold thenexisting between these elements is broken in a highly eli ective mannerand in one calculated to produce the least wear and tear on the parts athigh speed. Having thus started the armature in motion, quickacceleration is then desired to get the armature moving at high speedand when the armature has at tained the points are separated andmoreover, are separated at high speed to cause a. ouick break and onewhich is least apt to have detrimental eifects on the breaker points.Note that the breaker points do not separate during the initial movementof the arma ture. At this stage, the spring tension is diminishedalthough not entirely relaxed but separation of the points does notoccur until the abutments 28 and 29 engage and these engage only afterthe armature has acquired considerable speed. The breaker points beingclosed, the choke winding tends to prevent a rapid change of flux in themagnetic circuit and the breaker points may be likened to a valve for,as soon as they are opened, the flux is released and, the armaturehaving moved a considerable part of its stroke away from the poles andestablished a substantial air gap therebetween and acquired a high rateof speed, a sharp change efflux in the magnetic circuit ensues,resulting in the production of a substantial spark. I

The cam 41, as it moves through the angle 0, has no elfect in moving thearmature and the latter dwells in its lower position. As cam 41continues to move, however, the armature is moved toward its poles againand in a reverse manner to that already described. That is, it movesrapidly at first and progressively decreases in speed as it approachesthe poles. After the cam 41 has moved through the angle (Z, the armaturehas then approached as closely to poles 11 as the adjustment of the stud4O permits and dwells in this position during the travel of cam 44through angles 6 and a. Itis to be noted, however, that the breakerpoints are prevented'from closing during the upward flight of armature14 because at the time when cam 41 moved the armature into the lowermostposition the portion 56 of cam 53 came into action to lower the lever58. Thereafter, the armature moves toward poles 11, the head 64restrains the upward movement of breaker point 18, which would otherwisebe permitted by the armature. Consequently, the breaker points areallowed to engage only after cam 523 permits and this is permitted onlyafter the armature has attained the uppermost position and has rerequisite speed, the breaker:

mained in that position-long enougl'r to build up the desired-amount offlux in the mag netic circuit, at which time the lever 58 quic :lyreleases the breaker points and allowsthem quickly to en The generaloperation of the magneto having been explained, it ren'iains to considerthe special features relating to the means whereby the minimum air gapbe tween the armature and its poles may be varied; As above set forth,the arrangement is such that the armature ma contact with its poles,thus affording a minin'ium reluctance for the magnetic circuit by theentire elimination 0t air gaps, the reluctance of which, as is Wellknown, is ex,- ceedingly high. The provision for contact between thearmature and poles is desirable for starting because it is assumed thatrelatively low armature speeds will then be available.

After starting, the lever 50 is turned to varythe' position of stud sothat contact of the armature and poles is eliminated. By so'doing,the-noise and the Wear and tear on parts incident to such contact iseliminated and the electrical output is governed so thatit suiiicientfor low speeds it Will i not be excessive on high speeds. Theelimination of contact is a practical necessity in a magneto of thistype intended for high speed operation for by preventing contact ofarmature and poles, substantially all the noise of operation iseliminated and the magneto opera-tes very quietly and is sutlicientl-ynoiseless so that its use on an automobile is entirely unobjectionablefrom this point of view. There are no parts which are subjectedto heavyblows at high speed or e:\: ceptionally rapid Wear so that the life ofthe magneto can be at least as great as any 01 the magnetos ordinarilyused on automobiles. VJhile the eli-minataion of noise entails theexistence of air gaps between the armature and poles, higher armaturespeeds are available when used in the described n'ianner in connectionWith automobile engines, or other multicylinder types than in singlecylinder stationary engines, with which this type of magneto has beenassoci-' ated in the past. Armature speeds equal to,

)r greater, thanthose obtained by spring drive may be obtained and agreater armature speed can be chosen to compensate tor the necessary airgapslilagnets with higher flux values may oe chosen for the magneticsource to compensate for the presence of the air gaps. In fact, themagnetic flux and armature speeds may very easily be made suchthat it isnecessary during normal high speed operation to create the air gapbetiveen'the armature and its poles in order to prevent the generationof an excessive elect-remotes force which would puncture the windingsand otherwise work injury in.

the electrical circuits. The arrangement, however, is such that theminimum air gap may be varied, as desired, to secure the desiredresults. On some installations the minimum air gap may be as small as itcan be made Without actual contact occurring. On others, minimum ai-rgaps of greater degree'may be required and the adjustments describedallow one to control and govern the electrical output of the magneto asdesired.

In connect-ion With the means for varying the minimum air gap betweenthe armature and its poles and in addition to the important resultantadvantage of controlling the electrical output of the magneto asrequired, thereis another important feature which should be noted. Thearrangement is such that the operator cannot get aback kick by crankingthe engine even if the spark should be advanced. This result followsfrom the fact that anadvance in the timing of thejspark simultaneouslyeffects the creation of an air gap and the creation of an air gap soincreases the reluctance of the magnetic circuit that it is impossibleto get a sufiicient spark at cranking speeds under these conditions. 7

While the elimination of contact of the armature with its poles isimportant and essential to the practical and commercially satisfactoryoperation of a magneto, oft-he general class described, at high speeds,there is another important factor Which -con tributes substantially tothe successful operation of the magneto at high speed. This factor isthe means for preventing the breaker points from closing on the upstrokeof the armature. Nhile the flux can be built up in the magnetic circuitWith the choking WlIICllIIf short circuited, the action is necessarilyslow as the function of the choking Winding is to retard changes of fluxin the magnetic circuit. In low speed magnetos, suflicient time may beafforded in which to build up the flux against the short circuitedchoking Winding and thus decrease the noise due to the magneticattraction on the armature but in the present case the available timeinterval is very short and it is essential to eliminate every retardinginfluence. Consequently, the breaker points are purposely held open toexpedite the building up of the flux in the magnetic circuit and theelimination of the noise has been. otherwise provided for.

It is also to be noted that the timing ot the spark is determined by thetime of opening of the breaker points or by the time of engagement outabutments 28 and 29. This time may be varied by adjustment of theabutment 29 and obviously it may equally Well be varied by moving theabutment 28 instead. The adjustment of stud 40 by lever does, in. it? talso vary the timing toward or away from abutment 29.

and does so by adjusting the abutment 23 The time of flight of thearn'iatures may occur substantially at the same time in each revolutionof cam 41 but the time of spark may occur earlier or later according tothe distance existing between abntments 2S and 29, when the armature isin its uppermost position. When the armature is in contact with itspoles, the spark occurs later in the armature flight and thus later inthe revolution of shaft 42 than it does when the armatnr is positionedas shown in Fig. l. Consequently, when the lever 50 is manipulated tocause the armature to contact with its poles, for starting purposes, thespark is automatically retarded, as it should be, and independently ofthe operator, as is desirable. As lever 50 is moved to prevent contactofarmature and poles or to running position, the spark is at the same timeautomatically advanced.

I believe myself to be the first to provide a magneto of the generalclass described with operating mechanism whereby the degree of approachof the armature to its poles may be varied as desired and where thearmature can be made to contact wit-h its poles or not, according to thecondition desired. I also believe myself to be the first to provide, inconnection with breaker point mechanism. controlled from the armaturemovement, a supplementary controlling means independent of the armaturefor the general purposes set forth. Accordingly, I desire to claim myinvention in the broadest possible legal manner.

IV hat I claim is 1. In a magneto, of the type wherein a reciprocatingarmature is movable toward and away from a stationary magnetic pole tovary the reluctance of a magnetic circuit, means for varying thereciprocating movement of said armature to vary the degree to which thearmature approaches to said pole.

2. In a magneto, of the type-wherein an armature is movable toward andaway from a magnetic pole, controlling means operable on the armature toenable it to contact with said pole or be held from contact therewith asdesired.

In a magneto, of the type wherein an armature is movable toward and awayfrom a magnetic pole, means for controlling the movement of the armatureto enable the minimum air gap between the armature and said pole to bevaried.

l. In a magneto, of the type wherein an armature is reciprocable in astraight line toward and away from a stationary magnetic pole, means forvarying the minimum air gap between the armature and said pole, andreducii'ig it to Zero when desired.

In a magneto, of the type wherein an armature is movable into and out ofcontact with a ma netic pole, means acting on the armature to prevent itfrom being moved into contact with said pole when desired.

6. In a magneto, of the type wherein an armature is movable into and outof contact with a magnetic pole, means acting on the armature forpreventing such contact when desired without interfering with thefreedom of movement of the armature.

7. In a magneto, of the type wherein an armature is movable toward andaway from stationary magnetic poles, an operating shaft and connectionstherefrom to said armature for moving the latter from the former by aninelastic transmission of force therefrom at all times, and means forcontrolling the movement of the armature to thereby vary the minimum airgap between the armature and poles.

8. In a magneto, of the type wherein an armature is movable into and outof contact with stationary magnetic poles, an operating shaft andconnections therefrom to said armature for moving the latter from theformer by an inelastic transmission of force therefrom at all times, andadjustable means acting on the armature without interfering with itsfreedom of movement for preventing the armature from contacting withsaid poles.

9. In a magneto, of the type wherein an armature is movable toward andaway from a magnetic pole, means for reciprocating the armature, andmeans for varying the loca tion of the reciprocating movement withrespect to said pole.

10. In a magneto, of the type wherein an armature is movable toward andaway from a magnetic pole, means for reciprocating the armature, andmeans for varying the stroke of said movement to vary the degree towhich it approaches said pole at the end of one stroke of its movement.

11. In a magneto, of the type wherein an armature is movable toward andaway from a magnetic pole, means for varying the de gree to which thearmature approaches said pole, and means operable from the first namedmeans for varying the timing of the spark.

12. In a magneto, of the type wherein an armature is movable toward andaway from a magnetic pole, means tor varying the minimum air gap betweenthe armature and aid pole, and means for advancing or re tarding thespark generated accordingly as the minimum air gap is increased ordiminished, respectively.

13. In a magneto, of the type wherein an armature is movable toward andaway from a magnetic pole, means for controlling the degree to which thearmature approaches said pole and capable of allowing the armature tocontact'therewith, and means con ill) lid

lfiii tively ;movablebreaker points, an abutment on the armature, an'abutment carried by the movable breaker point adapted to be engaged bythe first named abutment to separate said points, meansyieldinglyholding said points 111 contactarid the second named. abutmentstationary with respect to saicktrame,means for operating the armature,and. means for adjusting the position of the latter with respect to saidpole to vary the spacing between said breaker points and the timing ofthe generated sparks.

15. In a magneto, of the type wherein an armature is movable toward andaway from amagnetic pole to vary the flux in the magnetic circuit aframe stationary with respect to said pole, cooperating and relativelymovable breakerpoints, an abutment carried by the movable breaker point,a second abutment, means for moving the latter from an initial positionto engage the first named abutment and separate the breaker points, andmeans for varying the initial position of the second abutment.

16. In a magneto, of the type wherein an armature is movable toward andaway from a magnetic pole to vary the flux in the magnetic circuit, aframe stationary with respect to said pole, cooperating and relativelymovable breaker points, an abutment carried by the movable breaker pointa second abutment, means for moving the latter from an initial positionto engage the first named abutment and separate the breaker points, andmeans operable during the operation of the armature and said mechanismto vary the initial position of the second abutment.

17. In a ma neto of the t )e wherein an from an initial posi tion inclose proximity to magnetic poles to a second position remote from saidpoles to generate a spark and immediately returns to said initialposition wherein it dwells until subsequently moved away to generateanother spark. a choking winding associated with said poles and arrangedin an electrical circuit which can be opened and closed, cooperating andrelatively movable breaker points for controlling the opening andclosing of said circuit, means adapted to hold said breaker points incontact when the armature occupies its initial and dwell position, meansoperable by n'ioven'ient ot the armature away from its poles torseparating said points after it has moved away from the initial positionand before it reaches the second position, and means for preventarmatureIllOVGS away ing or saidcircuit, means ing the breaker pointsiron'rcli-ising during the return movementof the arnniture and until ithas come to rest in'saidfldwell position.

18. In ihllligllGtO, or the type wherein an :e moves agvay from aninitial position in close pronimity'to magnetic poles toa'secondposition remotefrom said poles to generatea spark andimmediately returns to said initial position -wherein it dwells untilsubsequently moved away to generate another spark, a choking windingassociated 'with said poles and arranged in an elecandclosed,

trical circuit which. can be opened cooperating and relatively movablebreaker points tor controlling the opening and clos- 7 adapted to "holdsaid breaker points in contact when the armature occupies its initialand dwell position, means operable by movement of the armature awaytromits poles for separating said points atter it has moved away fromthe initial position and before it reaches the second position, andmeans to hold the breaker points open during the return stroke oi"- thearmature and for releasing them for closure under the first named meansafter the armature has come to rest and is dwelling in said initialposit-ion.

19. In a magneto, of the type wherein an armature is moved toward andaway from a magnetic pole, breaker point mechanism including a movablebreaker point, a drive shaft from which said armature is actuated, meanson the armature for moving said point in one direction and meansoperable from said shaft for controlling the move ment of said point inthe other direction.

20. In a magneto, of the type wherein an armature is moved toward andaway from a magnetic pole, breaker point mechanism including a movablebreaker point, a drive shaft from which said armature is actuated, meanscontrolled by movement of said armature for separating said points, andmeans controlled from said shaft for controlling the closing of saidpoints.

21. 111 a magneto, ot the type wherein an armature is moved'toward andaway from a magnetic pole, breaker point mechanism including a movablebreaker point, yieldable means tending to hold said points in contact,an abutment carried by said movable point, an abutment on the arn'iatureengageable with the first named abutment during its movement away fromthe pole to separate said points, and means for preventing said pointsfrom closing under the action of said yieldable means as the armaturemoves back toward said pole.

In a magneto, ot the type wherein an armature is moved toward and awayfrom a magnetic pole, breaker point mechanism including a movablebreaker point, yieldable means tending to hold said points in contact,an abutment carried by said movable point, an abutment on the armatureengageable with the first named abutmentduring its movement away fromthe pole to separate said points, a second abutment carried by saidmovable point and means independent of the movement of said armature forengaging the last named abutment and holding said breaker points openafter the first abutment on the movable point has been released by thecooperating abutment on said armature.

23. In a magneto, of the type wherein an armature moves toward and awayfrom a magnetic pole to vary the reluctance of a magnetic circuit byincreasing or diminishing an air gap therein, means for varying thedegree to which the armature approaches said pole to thereby vary theelectrical out put of the magneto and compensate for variations inarmature speed.

2%. In a magneto, of the type wherein an armature is movable toward andaway from a magnetic pole to vary the reluctnce of a magnetic circuit,means for varying the timing of the sparks generated by the magneto, andmeans controlled by the Variation in timing to increase or diminish theelectrical output of the magneto at any given armature speed accordinglyas the spark is retarded or advanced.

In testimony whereof I have aflixed my signature.

PHELPS BROWN.

